mirror of
https://github.com/neondatabase/neon.git
synced 2025-12-28 00:23:00 +00:00
f5db655447
## Problem LayerAccessStats contains a lot of detail that we don't use: short histories of most recent accesses, specifics on what kind of task accessed a layer, etc. This is all stored inside a Mutex, which is locked every time something accesses a layer. ## Summary of changes - Store timestamps at a very low resolution (to the nearest second), sufficient for use on the timescales of eviction. - Pack access time and last residence change time into a single u64 - Use the high bits of the u64 for other flags, including the new layer visibility concept. - Simplify the external-facing model for access stats to just include what we now track. Note that the `HistoryBufferWithDropCounter` is removed here because it is no longer used. I do not dislike this type, we just happen not to use it for anything else at present. Co-authored-by: Christian Schwarz <christian@neon.tech>